This invention relates to water supply systems.
It is known in the water supply system art to have a pressurized water tank communicating with a well pipe through a submersible pump. In these systems, the pump is controlled by a sensing system to maintain pressure in the water system. The water may be supplied to households or to other plumbing or water systems.
In one prior art water supply system of this type, the pressure tank and associated equipment are mounted in a pit. The well casing extends upwardly into the bottom of the pit and connected there to pipes leading to the pressure tank where access is available to the connection. This arrangement has a serious disadvantage in that the pit accumulates waste water and the like and may permit contaminants to drain into the well.
In another class of prior art water supply systems known as pitless systems, this disadvantage is avoided by using a pitless unit or pitless adapter which is a unit that connects to the well casing, usually below the frost line, and conducts water to a pressure tank, protects the water from freezing and prevents the entry of contaminants. In a common type of pitless system, the pitless unit rests on the well casing below ground and extends upwardly to the surface. This type of pitless unit is approximately the same size as the well casing or one nominal size larger in the case of a spool type outlet to the plumbing system of the user. Usually, the pumps are driven by a constant speed motor that operates in duty cycles, has relatively constant flow rates depending on the efficient running speed of the pump motor but has different frequencies of the cycles of pumping and not pumping or durations of the cycles of pumping and not pumping that depend on the demand for water. The pressure tank is mounted separately from the well such as in a home or separate opening in the ground below the frost line or building near the well. The pressure tanks are sufficiently large to provide water under adequate pressure under different demand conditions with the same flow rate from the pumps but different frequencies of cycles or different duty cycles.
It is known to use variable speed pumps in water supply systems. Moreover, it is known to improve existing systems with a pit by sealing the pit with an enlarged housing of sufficient size to fill the pit, but these prior art retrofit systems also have large pressure tanks and the pressure tanks are mounted separately from the well.
This type of prior art water supply module has several disadvantages such as for example: (1) the size of pressure tank needed to satisfy demand for some plumbing systems is relatively large; (2) a separate building or space in the building receiving water from the well or other underground opening is needed for the pressure tank; and (3) they are relatively expensive to install, under some circumstances, because the pressure tank is located or housed at a location spaced from the well.